From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 13344C43381 for ; Mon, 25 Feb 2019 21:33:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CAD692184E for ; Mon, 25 Feb 2019 21:33:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1551130383; bh=0zDiPmVkUEvZyn73qqOjUpUORJATscU+F4gpodlUt0A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=XeNIWBkWFr+yfpjEks40CJukM20AiPe0rHnKCUd0BXzBRLO6vpqVYGbXgD9rlQ3IQ ey6U9+lBTXeO3OE59HB2ew+xKAWW+AE2wB+lThQHtDJrGLzSH9PV8piV3AoW9nOt4+ /qYoxP6mN9IClDGBnfQWaNp2XlBpe3iJEhlUKWSM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732594AbfBYVdC (ORCPT ); Mon, 25 Feb 2019 16:33:02 -0500 Received: from mail.kernel.org ([198.145.29.99]:38960 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732580AbfBYVc7 (ORCPT ); Mon, 25 Feb 2019 16:32:59 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 10EDB2184D; Mon, 25 Feb 2019 21:32:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1551130378; bh=0zDiPmVkUEvZyn73qqOjUpUORJATscU+F4gpodlUt0A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YkfG3dG/NPRN8ob89KMTom0GNN8z5fL+72FN8BivqoWpchs9cj+Ich+mGs2MW4kxY iex8fZ9mdhOk2J7Y2VdFiqdGrHe17GiGFo1FoB3WMubJgCN5GkQ5O5So949XaHVtYK hd3iCMFcQGKFTltTfSVdcuLaxuwzTKb0qvZMra50= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Naresh Kamboju , Song Liu , Daniel Borkmann , Sasha Levin Subject: [PATCH 4.20 065/183] bpf: fix panic in stack_map_get_build_id() on i386 and arm32 Date: Mon, 25 Feb 2019 22:10:38 +0100 Message-Id: <20190225195105.488099969@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190225195054.748060397@linuxfoundation.org> References: <20190225195054.748060397@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.20-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit beaf3d1901f4ea46fbd5c9d857227d99751de469 ] As Naresh reported, test_stacktrace_build_id() causes panic on i386 and arm32 systems. This is caused by page_address() returns NULL in certain cases. This patch fixes this error by using kmap_atomic/kunmap_atomic instead of page_address. Fixes: 615755a77b24 (" bpf: extend stackmap to save binary_build_id+offset instead of address") Reported-by: Naresh Kamboju Signed-off-by: Song Liu Signed-off-by: Daniel Borkmann Signed-off-by: Sasha Levin --- kernel/bpf/stackmap.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c index 90daf285de032..d9e2483669d0b 100644 --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -260,7 +260,7 @@ static int stack_map_get_build_id(struct vm_area_struct *vma, return -EFAULT; /* page not mapped */ ret = -EINVAL; - page_addr = page_address(page); + page_addr = kmap_atomic(page); ehdr = (Elf32_Ehdr *)page_addr; /* compare magic x7f "ELF" */ @@ -276,6 +276,7 @@ static int stack_map_get_build_id(struct vm_area_struct *vma, else if (ehdr->e_ident[EI_CLASS] == ELFCLASS64) ret = stack_map_get_build_id_64(page_addr, build_id); out: + kunmap_atomic(page_addr); put_page(page); return ret; } -- 2.19.1